Process of conducting electrolysis.



ERNEST A. LE SUEUR, OF OTTAWA, ONTARIO, CANADA.

PROCESS OF CONDUCTING ELECTROLYSIS.

No Drawing.

To all whom it may concern:

Be it known that I, ERNEST A. LE SUEUR,

-a subject of the King of Great Britain, re-

siding at Ottawa, in the county of Carleton and Province of Ontario, Canada, have invented new and useful Improvements in Processes of, Conducting- Electrolysis, of which the following is a specification.

My invention presents improved means for enhancing the efficiency of electrolytic cells used for the production of chlorates by the electrolysis of chlorid solutions.

Hitherto it has been Well known to use separately either a dilute solution of a salt of chromic acid 'or the so-called lime diaphragm (obtained by adding calcium chlorid to the solution under electrolysis) for the purpose of minimizing cathodic reduction. In cells hitherto known to be constructed and used a trifling amount of the selected reagent is found to effect the desired result.

I have found notable commercial advantages to attend the use of types of chlorate electrolyzers employing a very low current density provided only that cathodic reduction can be minimized. In my attempts to v achieve this result in this connection I have discovered that neither the lime diaphragm nor the salt 'of chromic acid, in any practicably feasible amounts, is capable of sufficiently suppressing said reduction, but that if to an electrolytic bath in which either is already in-use a suitable small addition of the other is made the difficulty is immediately solved, and that the employment of a small quantity of the two in combination exerts an influence on such suppression out Specification of Letters Patent.-

Patented Apr. 15, 1919..

Application filed July 19, 1918. Serial No. 245,785.

of all proportion to that obtained by doubling either; the combination thus present ing a specific advantage and not a' mere additive effect. This is important not only from the standpoint of efficiency but also because any large additions of either reagent, in the effort to improve its effect, are commercially disadvantageous; in the case of the salt of chromio acid by reason of their cost and the necessity of getting rid of the strong yellow color in the product to make it merchantable, and in that of the lime because of the extra electrical resistance due to its use and the fact that most of it ultimately forms muds.

While I do not wish to limit myself as to the proportions of both or either of the said reagents I prefer to employ about one third of 1% of an alkali bichrom'ate in the solution and a daily addition of about 0.0008

grm. of calcium chlorid or its equivalent.

bination an alkaline earth coating on the I cathode and a salt of chromic acid in solution in the electrolyte.

2. In cells used for preparing chlorates by the electrolysis of chlorid solutions, in combination a lime coating on the cathode and a salt of chromic acid in solution in the electrolyte;

ERNEST A. LE SUEUR. 

